Intestinal sleeve

ABSTRACT

A gastrointestinal implant device is anchored in the duodenum and extends beyond the ligament of Treitz. All food exiting the stomach is funneled through the device. The gastrointestinal device includes an anchor for attaching the device to the duodenum and an unsupported flexible sleeve. The anchor can include a stent and/or a wave anchor and is collapsible for catheter-based delivery and removal.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/493,487, filed Jul. 26, 2006, now U.S. Pat. No. 7,682,330 which is adivisional of U.S. application Ser. No. 10/858,851, filed Jun. 1, 2004,now U.S. Pat. No. 7,476,256 which claims the benefit of U.S. ProvisionalApplication No. 60/528,084, filed Dec. 9, 2003 and U.S. ProvisionalApplication No. 60/544,527, filed Feb. 13, 2004. The entire teachings ofthe above application are incorporated herein by reference.

BACKGROUND OF THE INVENTION

According to the Center for Disease Control (CDC), over sixty percent ofthe United States population is overweight, and almost twenty percentare obese. This translates into 38.8 million adults in the United Stateswith a Body Mass Index (BMI) of 30 or above. The BMI is defined as aperson's weight (in kilograms) divided by height (in meters), squared.To be considered clinically, morbidly obese, one must meet one of threecriteria: BMI over 35, 100 lbs. overweight or 100% above ideal bodyweight. There is also a category for the super-obese for those weighingover 350 lbs.

Obesity is an overwhelming health problem. Because of the enormousstrain associated with carrying this excess weight, organs are affected,as are the nervous and circulatory systems. In 2000, the NationalInstitute of Diabetes, Digestive and Kidney Diseases (NIDDK) estimatedthat there were 280,000 deaths directly related to obesity. The NIDDKfurther estimated that the direct cost of healthcare in the USassociated with obesity is $51 billion. In addition, Americans spend $33billion per year on weight loss products. In spite of this economic costand consumer commitment, the prevalence of obesity continues to rise atalarming rates. From 1991 to 2000, obesity in the US grew by 61%. Notexclusively a US problem, worldwide obesity ranges are also increasingdramatically.

One of the principle costs to the healthcare system stems from theco-morbidities associated with obesity. Type-2 diabetes has climbed to7.3% of the population. Of those persons with Type-2 diabetes, almosthalf are clinically obese, and two thirds are approaching obese. Otherco-morbidities include hypertension, coronary artery disease,hypercholesteremia, sleep apnea and pulmonary hypertension.

Although the physiology and psychology of obesity are complex, themedical consensus is that the cause is quite simple—an over intake ofcalories combined with a reduction in energy expenditures seen in modernsociety. While the treatment seems quite intuitive, the institution of acure is a complex issue that has so far vexed the best efforts ofmedical science. Dieting is not an adequate long-term solution for mostpeople. Once an individual has slipped past the BMI of 30, significantchanges in lifestyle are the only solution.

There have been many attempts in the past to surgically modify patients'anatomies to attack the consumption problem by reducing the desire toeat. Stomach saplings, or gastroplasties, to reduce the volumetric sizeof the stomach, therein achieving faster satiety, were performed in the1980's and early 1990's. Although able to achieve early weight loss,sustained reduction was not obtained. The reasons are not all known, butare believed related to several factors. One of which is that thestomach stretches over time increasing volume while psychologicaldrivers motivate patients to find creative approaches to literally eataround the smaller pouch.

There are currently two surgical procedures that successfully producelong-term weight loss; the Roux-en-Y gastric bypass and thebiliopancreatic diversion with duodenal switch (BPD). Both proceduresreduce the size of the stomach plus shorten the effective-length ofintestine available for nutrient absorption. Reduction of the stomachsize reduces stomach capacity and the ability of the patient to take infood. Bypassing the duodenum makes it more difficult to digest fats,high sugar and carbohydrate rich foods. One objective of the surgery isto provide feedback to the patient by producing a dumping syndrome ifthey do eat these food products. Dumping occurs when carbohydratesdirectly enter the jejunum without being first conditioned in theduodenum. The result is that a large quantity of fluid is dischargedinto the food from the intestinal lining. The total effect makes thepatient feel light-headed and results in severe diarrhea. For reasonsthat have not been determined the procedure also has an immediatetherapeutic effect on diabetes.

Although the physiology seems simple, the exact mechanism of action inthese procedures is not understood. Current theory is that negativefeedback is provided from both regurgitation into the esophagus anddumping when large volumes of the wrong foods are eaten. Eventually,patients learn that to avoid both these issues they must be compliantwith the dietary restrictions imposed by their modified anatomy. In theBPD procedure, large lengths of jejunum are bypassed resulting inmalabsorption and therefore, reduced caloric uptake. In fact, thestomach is not reduced in size as much in the BPD procedure so that thepatient is able to consume sufficient quantities of food to compensatefor the reduced absorption. This procedure is reserved for the mostmorbidly obese as there are several serious side effects of prolongedmalabsorption.

Unfortunately, these procedures carry a heavy toll. The morbidity ratefor surgical procedures is alarmingly high with 11% requiring surgicalintervention for correction. Early small bowel obstruction occurs at arate of between 2-6% in these surgeries and mortality rates are reportedto be approximately 0.5-1.5%. While surgery seems to be an effectiveanswer, the current invasive procedures are not acceptable with thesecomplication rates. Laparoscopic techniques applied to these surgeriesprovide fewer surgical complications but continue to expose these veryill patients to high operative risk in addition to requiring an enormouslevel of skill by the surgeon. Devices to reduce absorption in the smallintestines have been proposed (See U.S. Pat. No. 5,820,584 (Crabb), U.S.Pat. No. 5,306,300 (Berry) and U.S. Pat. No. 4,315,509 (Smit)). However,these devices have not been successfully implemented.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for theapplication of a barrier sleeve in the digestive tract to limitabsorption of food products in specific parts of the digestive tract andto provide negative feedback to patients with morbid obesity enablingthem to modify their heating habits. The sleeve may also be used forother treatments such as Type-2 diabetes.

A gastrointestinal implant device includes an unsupported flexiblesleeve and an anchor coupled to a proximal portion of the sleeve. Theflexible sleeve is open at both ends, and adapted to extend into theduodenum to limit absorption of nutrients in the duodenum. The anchor isadapted to be retained within the duodenum, particularly in the duodenalbulb just distal to the pylorus.

The anchor may be collapsible for ease of insertion and/or removal in aminimally. For example, the anchor may be inserted and/or removedendoluminally using a catheter-based procedure. The collapsible anchoris also well adapted for insertion into the duodenum, being capable ofcollapsing and/or flexing in response to natural movements of the localanatomy. The anchor can be covered by a proximal portion of the sleeve,and in some embodiments is sandwiched between a first inner layer and asecond outer layer of the sleeve. The sleeve is of a length that chymeexiting the stomach funneled through the proximal end of the sleeveexits the sleeve through the distal end. The length of the sleeve can bevaried. In some embodiments, the sleeve extends below the ligament ofTreitz. In preferred embodiments, the sleeve material has a coefficientof friction of less than about 0.2. The sleeve may be formed of abiocompatible, low-friction material such as a fluoropolymer. In someembodiments, the sleeve is formed from PolyTetraFluoroEthylene (PTFE),expanded PTFE (ePTFE), or polyolefin (e.g., as a low densitypolyethylene film). Additionally, the sleeve may be coated orimpregnated with a second material, such as polyurethane or silicone toreduce permeability. Still further, the distal end of the sleeve may bedirectionally textured.

The anchor can be attached to the surrounding anatomy using mechanicalfasteners, such as sutures, surgical staples. In some embodiments, themechanical fasteners can be dissolvable, dissolving after apredetermined time and allowing the device to pass naturally. In otherembodiments, the anchor is attached to the surrounding anatomy using aninterference fit provided by the relative size of the anchor in relationto the surrounding anatomy. Alternatively or in addition, the anchor canbe attached to the surrounding anatomy using chemical fasteners, such assurgical adhesives.

Mechanical fasteners include barbs that extend from the exterior surfaceof the anchor for anchoring the proximal portion of the sleeve to themuscular tissue of the surrounding anatomy. The barbs may bebi-directional for anchoring the proximal portion of the flexible sleeveto the duodenum. Alternative anchors coupled to a proximal portion ofthe sleeve include a ring, a stent formed by a network of struts, or awire formed as a wave.

An anti-buckling device may also be coupled to the sleeve and extendfrom below the anchor to the distal end of the flexible sleeve to reducetwisting and buckling of the sleeve. The sleeve allows enzymes secretedin the duodenum to pass through the duodenum outside the sleeve.

The gastrointestinal implant device can be inserted endoluminally incombination with a delivery catheter and can be similarly removed incombination with a removal device. More generally, the device can beimplanted through a natural body lumen, such as per-orally and/orper-anally. Alternatively or in addition, the device can be implantedpercutaneously. In one embodiment, the delivery apparatus includes acatheter for passage through the intestines and a spherically-shapedelement coupled to the distal end of the catheter. In some embodiments,the spherically-shaped element can be remotely releasable.

In another aspect, a gastrointestinal implant device includes anunsupported flexible sleeve and a wave anchor coupled to a proximalportion of the sleeve. The wave anchor includes a compliant, radialspring shaped into an annular wave pattern about a central axis,providing an outward radial force, while allowing substantial flexureabout its perimeter. Such flexure is advantageous as it allows forminimally-invasive delivery and ensures that the device willsubstantially conform to the surrounding anatomical structure whenimplanted. The annular wave element can be formed from one or moreelongated resilient members and defines a lumen along its central axisformed between two open ends. When implanted, the central axis of theanchor is substantially aligned with the central axis of the duodenum,allowing chyme to pass through the device. Additionally, the compliantwave anchor minimizes trauma to the tissue by providing sufficientflexibility and compliance, while minimizing the likelihood of tissueerosion and providing a solid anchoring point to the tissue.

The anchor can be removably attached within the body using any of themethods described herein for securing an anchor, including the use ofbarbs attached to, and/or formed on the anchor itself. When implanted,the anchor enables a sleeve, or barrier to be securely implanted withinthe duodenum, preferably providing a fluid seal at the proximal end. Toenhance a fluid seal, the proximal end of the sleeve can be contouredalong a leading edge of the wave anchor. In this manner, substantiallyno unsupported sleeve remains proximal to the wave anchor. Thus, chymeis allowed to flow substantially unimpeded into the sleeve withoutbecoming entrapped at the anchor.

The gastrointestinal implant device can be used in a method for treatingintestinal bowel disease. An unsupported flexible sleeve is anchoredwithin the duodenum. The sleeve is open at both ends and may beimpregnated with a drug that reduces inflammation.

The gastrointestinal implant device can be used as a method for treatingobesity. An unsupported flexible sleeve is anchored within the duodenum.The sleeve is open at both ends and enhanced with anti-hunger hormones.

The gastrointestinal implant device can be used as a method for treatingType-2 diabetes. A proximal portion of an unsupported flexible sleeve,open at both ends, is coupled to a collapsible anchor. The anchorincludes barbs for insertion into tissue as the anchor expands to anchorthe proximal portion of the sleeve in the duodenum. The flexible sleeveis extended at least into the duodenum to limit the digestion and/orabsorption of nutrients.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 is a sectional view of a portion of the digestive tract in abody;

FIG. 2 is a perspective view of a gastrointestinal implant deviceaccording to the principles of the present invention;

FIG. 3A is a plan view of the proximal portion of the gastrointestinalimplant device shown in FIG. 2;

FIG. 3B is a cross-sectional view as taken along line A-A of FIG. 3Ashowing the anchor and first inner layer and second outer layer of thesleeve shown in FIG. 2;

FIG. 4 is a perspective view of the gastrointestinal implant device withthe second outer layer of the sleeve removed;

FIG. 5 is a sectional view of a body showing the gastrointestinalimplant device implanted in the digestive system;

FIG. 6 is a perspective view of a collapsible self-expanding anchor inthe gastrointestinal implant device;

FIG. 7 is a perspective view of the anchor shown in FIG. 6 whencompressed;

FIG. 8 is a perspective view of another embodiment of a anchor whencompressed;

FIG. 9 is a perspective view of the anchor shown in FIG. 8 with thestrut ends bent to provide opposed barbs;

FIG. 10 is a perspective view of the anchor shown in FIG. 8 whenexpanded;

FIG. 11 illustrates the gastrointestinal device shown in FIG. 1including an anti-buckling mechanism;

FIG. 12 is a perspective view of a catheter system for delivery of thegastrointestinal implant device;

FIG. 13 is a cross-sectional view of the inner shaft taken along lineE-E of FIG. 12;

FIG. 14A is an expanded perspective view of the dead-bolt mechanismshown in FIG. 12;

FIG. 14B is a sectional view of the dead-bolt mechanism shown in FIG.13A illustrating the sleeve retention wire threaded through the sleeve;

FIG. 15 is sectional view of a portion of the catheter systemillustrating the collapsed anchor stored inside the outer sheath;

FIG. 16A is a plan view of the catheter system illustrating thecollapsed anchor stored inside the outer sheath of the gastrointestinalimplant device;

FIG. 16B is a plan view of the catheter system illustrating thegastrointestinal implant device after release of the anchor from theouter sheath;

FIG. 16C is a plan view of the catheter system illustrating the expandedgastrointestinal implant device after the sleeve retention wire has beenreleased;

FIG. 17 is a perspective view of another embodiment of the cathetersystem shown in FIG. 12;

FIG. 18 is a sectional view of an everting catheter system for deliveryof a longer length sleeve;

FIG. 19 is a perspective view of a retrieval device for removing thegastrointestinal implant device from the digestive tract;

FIG. 20 is a perspective view of the removal device engaged with theanchor;

FIG. 21 is a perspective view of another embodiment of agastrointestinal implant device;

FIG. 22 is a perspective view of the anchoring ring shown in FIG. 21;

FIG. 23 is a perspective view of the anchoring ring shown in FIG. 21 ina collapsed position for insertion and removal;

FIG. 24 is a perspective view of an anchor for anchoring the collapsiblering shown in FIG. 23 to the muscular tissue of the duodenum;

FIG. 25A is a perspective view of a delivery system for delivering theanchor after the gastrointestinal implant device has been placed in theduodenum;

FIG. 25B is a plan view of the delivery system shown in FIG. 25A;

FIG. 25C is a cross-sectional view of the distal end of the catheter astaken along line B-B of FIG. 25A;

FIG. 25D is a perspective view of the gastrointestinal implant deviceillustrating the anchor engaged with the tissue;

FIG. 25E is an isometric view illustrating the barb engaging the tissueafter delivery;

FIG. 26A is a plan view of the delivery system including a snare wirefor holding the distal end of the sleeve in position;

FIG. 26B is a cross-sectional view taken along line CC of FIG. 26Athrough the inner sheath;

FIG. 26C is a cross-sectional view taken along line DD of FIG. 26Athrough the outer sheath showing the inner sheath within the outersheath;

FIG. 26D is a cross-sectional view through the distal portion of thecatheter showing the snare capturing the distal end of the sleeve;

FIG. 26E is a sectional view through the distal portion of the cathetershowing the snare locking mechanism;

FIG. 27 is a perspective view of the distal portion of thegastrointestinal implant device including texturing at the distal end;

FIG. 28 is a perspective view of a gastrointestinal implant device withanother embodiment of an anchoring device;

FIG. 29 is a more-detailed perspective view of the anchoring device ofFIG. 28;

FIG. 30 is a is a sectional view of a body showing the gastrointestinalimplant device of FIG. 28 implanted in the digestive system;

FIG. 31 is a perspective view of an alternative embodiment of thegastrointestinal implant device of FIG. 28;

FIG. 32A is a perspective view of a portion of a catheter system fordelivery of a gastrointestinal implant device;

FIG. 32B is a cross-sectional view of the catheter shaft taken alongline 42B-42B of FIG. 32A;

FIG. 33 is a sectional view of a portion of the digestive tract in abody illustrating the position of a gastroscope/guide tube assembly;

FIG. 34 is a sectional view of a portion of the digestive tract in abody illustrating the distal end of the catheter extending from thedistal end of the guide tube 4300;

FIG. 35 is a sectional view of a portion of the digestive tract in abody after the gastrointestinal implant device of FIG. 28 has beendelivered;

FIG. 36 is a plan view of the distal end of the catheter systemillustrating a releasable ball tip mechanism;

FIG. 37 is a plan view of the distal end of the catheter illustrating analternative embodiment of a releasable ball tip mechanism;

FIG. 38 is a plan view of the distal end of the catheter illustratingyet another embodiment of a releasable ball tip mechanism;

FIG. 39 is a cross sectional view of an alternative embodiment of asolid spherical shaped element;

FIG. 40A is a plan view of the distal end of the catheter with aninflatable spherical shaped element;

FIG. 40B is a plan view of the distal end of the catheter after theinflatable spherical shaped element has been inflated;

FIG. 41 is a plan view of an alternative delivery system for deliveringa gastrointestinal implant device;

FIG. 42 is a plan view of another embodiment of the delivery mechanismshown in FIG. 41;

FIGS. 43A-43C illustrate a method for delivering an alternate embodimentof the catheter system 4250 having a central lumen for placement over aguide wire;

FIG. 44 is a graph of representative compliance curves for differentembodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

A description of preferred embodiments of the invention follows. FIG. 1is a sectional view of a portion of the digestive tract in a body. Foodto be digested enters the stomach 102 through the cardiac orifice 110from the esophagus. Chyme, a semi-fluid, homogeneous creamy orgruel-like material produced by gastric digestion in the stomach exitsthe stomach through the pyloric orifice (pylorus) 108 and enters thesmall intestine 112. The pylorus 108 is a distal aperture of the stomach102 surrounded by a strong band of circular muscle. The small intestine,about nine feet in length, is a convoluted tube, extending from thepylorus 108 to the ileo-caecal valve where it terminates in the largeintestine. The small intestine has three sections, the duodenum 104,jejunum 106 and the ileum (not shown). The first eight to ten inchsection of the small intestine 112, the duodenum 104, is the shortest,widest and most fixed part of the small intestine 112.

The duodenum 104 has four sections: superior, descending, transverse andascending which typically form a U-shape. The superior section is abouttwo inches long and ends at the neck of the gall bladder. The superiorsection also defines a feature referred to as the duodenal bulb 119 thatbegins just distal to the pylorus 108 and extends for about 1 to 1.5inches in an adult human. The duodenal bulb 119 defines a lumen thereinthat is slightly larger than the distal duodenum 104. Advantageously,the duodenal bulb 119 exhibits less motion than the pylorus 108 and evendistal portions of the duodenum 104. Notably, the motion issubstantially limited to contractions without having a significantlinear component (i.e., no movement along the central axis of theintestine). However, the tissue thins as one moves away from the pylorus108.

The descending section of the duodenum 104 is about three to four incheslong and includes a nipple shaped structure (papilla of Vater) 114through which pancreatic juice from the pancreas and bile produced bythe liver and stored by the gall bladder enter the duodenum from thepancreatic and bile ducts. The pancreatic juice contains enzymesessential to protein digestion and bile dissolves the products of fatdigestion. The ascending section is about two inches long and forms theduodenal-jejunal flexure 116 where it joins the jejunum 106, the nextsection of the small intestine. The duodenal-jejunal flexure 116 isfixed to the ligament of Treitz 118 (musculus supensionus duodeni). Thejuices secreted in the duodenum break the partially digested food downinto particles small enough to be absorbed by the body. The digestivesystem is described in Gray's Anatomy (“Anatomy of the Human Body,” byHenry Gray) and “Human Physiology,” Vander, 3^(rd) ed, McGraw Hill,1980, the contents of which are incorporated herein by reference intheir entirety.

FIG. 2 is a perspective view of a gastrointestinal implant device 200according to the principles of the present invention. Thegastrointestinal implant device 200 includes an elongated, open-ended,unsupported flexible sleeve or tube 202 having a first proximal opening204 and a second distal opening 206. Within the sleeve 202 is apassageway that extends from the first proximal opening 204 to thesecond distal opening 206 for transporting the chyme exiting the stomach102 (FIG. 1). The surface of the passageway (the interior surface of theimplant device 200) is smooth to enable the chyme to easily passthrough. The exterior surface of the implant device 200 is smooth toprevent tissue in-growth and to be non-irritating to the bowel.

Within the implant device 200 at the proximal end including the firstproximal opening 204 is a collapsible self-expanding anchor 208. Theanchor 208 includes a plurality of opposed barbs 210 for anchoring theimplant device 200 to the muscular tissue of the duodenum 104. Thediameter of the anchor 208 is dependent on the diameter of the duodenum104 (FIG. 1) about 1.0″ to 2.5″ based on human anatomy variations. Inone embodiment, the length ‘l’ of the anchor 208 is selected to residewithin the bulbous duodenum 119.

Anchoring in the bulbous duodenum 119 offers several advantages overother areas in of gastrointestinal tract. First, the duodenal bulb 119is proportionally sized to capture an anchor—that is it provides acavity having a relatively large diameter bounded by anatomies havingsmaller diameters in both the proximal and distal directions. Thus, theduodenal bulb 119 is naturally configured to retain a suitably-shapedanchor.

Additionally, the duodenal bulb 119 is relatively less active than theeither the pylorus or distal portions of the duodenum. The duodenal bulb119 at least in part acts as a holding area for chyme received from thestomach. Thus, the duodenal bulb 119 provides a more stable anchoringplatform as there is less movement there. Movement of the surroundingtissue can act to dislodge an anchor over time. Still further, as thetissue of at least the proximal portion of the duodenal bulb 119 isthicker than the tissue of the distal duodenum. Thus, the duodenal bulb119 provides a better anchoring platform as it is adapted to regainlonger fasteners (e.g., longer barbs).

The sleeve material is thin and conformable so that it collapses in theintestine to a small volume to minimize bowel irritability. It has a lowcoefficient of friction (less than about 0.20) so that chyme slideseasily through it and the bowel slides easily around it. It is of lowpermeability to fluids so that the chyme does not touch the bowel walland the digestive enzymes do not significantly breakdown the chyme. Itis biologically inert and non-irritating to the tissues. One class ofmaterials includes fluoropolymers. In some embodiments, the sleeve isformed from expanded PTFE with a wall thickness of about 0.006 inchesand an internodal distance of 20 microns. This material is hydrophobicbut is slightly porous. However, these very small pores may plug overtime. The porosity may be reduced by coating the material on the inside,outside or in the pores with dilute solutions of silicone orpolyurethane. Another material is polyethylene with a wall thickness ofless than 0.001 inches. Other materials include CastPolyTetraFluoroEthylene (PTFE, e.g., TEFLON), Cast PTFE with FluorinatedEthylene Propylene (FEP) or PerFluoroAlkoxy (PFA) coating to minimizepin holes, Extruded FEP and Extruded PFA. These materials are solid andsubstantially non-porous in contrast to ePTFE which is porous, but thesematerials are also considered to be fluoropolymers. The wall thicknessis preferably less than about 0.001 inches. Rubber-like materialstypically have friction coefficients of about 1-4, significantlystickier than these materials. However, in alternate embodiments othermaterials having similar characteristics can be used.

In some embodiments, the sleeve is formed using a combination of two ormore materials. For example, the sleeve can be formed using acombination of ePTFE and FEP. Such a combination can be formed bylayering the two materials together and generally provides a lowcoefficient of friction while being substantially non-permeable.

The sleeve 202 includes two layers of material at least at the proximalend. A first outer layer covers the exterior of the anchor 208. Thesecond inner layer covers the interior surface of the anchor 208. Thebarbs 210 protrude from the exterior surface of the anchor 208 throughthe first outer layer of the sleeve 202. The holes in the first outerlayer through which the barbs 210 protrude can be filled with animpervious material such as silicone or urethane to limit mixing ofdigestive juices with the chyme flowing through the passageway. Thediameter of the sleeve 202 is selected such that the first outer layerof the sleeve 202 fits over the anchor 208.

The sleeve length 212 is variable and can range from about one foot toabout five feet. The typical length of the sleeve 202 is about 2 to 4feet measured from the anchor (barbs 210) in the bulbous duodenum 119 tobelow the ligament of Treitz 118 (FIG. 1). The length 212 of the sleeve202 is selected to bypass the duodenum 104 (FIG. 1) and a portion of thejejunum 106. The length can optionally be increased to further decreaseabsorption by bypassing a longer section of the jejunum 106 (FIG. 1).Thus, the length 212 of the sleeve 202 is variable and may be dependenton the patient's Body Mass Index (BMI). The procedure is a less invasivealternative to surgery for the treatment of obesity and morbid obesityand also provides a new treatment approach for Type-2 diabetes.

The covered anchor 208 can be collapsed into a sheath having a diameterless than about 12 mm or less to enable endoluminal and/orcatheter-based delivery. Covering the exterior surface of the anchor 208with the first outer layer of the sleeve 202 permits catheter-basedremoval of the implant device 200 by preventing tissue in-growth on theexterior surface of the anchor 208.

Additionally, markings can be added to the exterior surface of thesleeve 202 to detect the position and orientation of the sleeve on afluoroscopic image and whether the sleeve is twisted. For example, aradiopaque stripe can be painted down the length of the device 200 usingtantulum impregnated ink, or tantulum bands can be bonded to a surfaceof the device, such as the interior surface. If the sleeve 202 istwisted, the sleeve 202 can be untwisted by inserting a balloon into theproximal end of the device thereby sealing it, and then injecting waterinto the sleeve 202 at low pressure. More generally, a radiopaquemarking can also be used to facilitate placement and/or removal of thedevice.

FIG. 3A is a plan view of the proximal portion of the gastrointestinalimplant device 200 shown in FIG. 2. FIG. 3B is a cross-sectional view astaken along line AA of FIG. 3A showing the anchor 208 and the firstouter layer 300 and the second inner layer 302 of the sleeve 202 shownin FIG. 2. As described in conjunction with FIG. 2, the sleeve 202includes a first outer layer 300 and a second inner layer 302. The firstouter layer 300 is bonded to the second inner layer 300 at positions 306below the distal end of the anchor 208 and at positions 308, above theproximal end of the anchor 208. A passageway 304 inside the second innerlayer 302 of the sleeve 202 allows passage of chyme through the sleeve202. The anchor 208 is sandwiched between the first outer layer 300 andthe second inner layer 302 at the proximal end of the sleeve 202 and isfree to move at the distal end within the first outer layer 300 and thesecond inner layer 302 of the sleeve 202. The covered exterior surfaceof the anchor 208 prevents tissue growth that could otherwise hinderremoval of the implant device 200. The covered interior surface of theanchor 208 provides a smooth passageway for chyme to bypass the duodenum104.

FIG. 4 is a perspective view of the gastrointestinal implant device 200with the first outer layer 300 of the sleeve 202 removed. Theinterconnecting struts which form the mesh (a network of struts) withdiamond spaced openings are sufficiently flexible to allow the anchor tobe collapsed inside a delivery catheter and have sufficient elasticityto engage the interior walls of the covered region of the intestine oncethe catheter is withdrawn. The force needed to provide a fluid seal isprovided when the anchor 208 is compressed from its full diameter (e.g.,an anchor having a relaxed diameter of about 1.75 inches and animplanted diameter of about 1.5 inches).

FIG. 5 is a sectional view of a body showing the gastrointestinalimplant device 200 implanted in the digestive system. The first proximalend 204 of the implant device 200 is anchored to the duodenum 104. Thebarbs 210 grip onto the muscular tissue to anchor the implant device 200in place so that the implant device 200 can not be dragged into thestomach 102 or down into the intestines with movement of the stomach 102and the intestines.

The sleeve 202 can extend over the ligament of Treitz 118 beyond theproximal jejunum 106. Extending the sleeve 202 below the ligament ofTreitz 118 reduces the likelihood that the sleeve 202 will move backthrough the duodenum 104 toward the stomach 102.

After the gastrointestinal implant device 200 has been placed in thebody and anchored in the duodenum 104, chyme leaving the stomach passesthrough passageway 304 (FIG. 3B) inside the sleeve 202 and bypasses theduodenum 104 and proximal jejunum 106. By directing the chyme throughthe sleeve 202 the digestion and the absorption process in the duodenum104 is interrupted. By interrupting mixing of the chyme with juices inthe duodenum 104, partially digested food material is not broken downinto particles small enough to be absorbed by the body. Further, thereis no mixing of bile with the chyme until the chyme reaches the jejunum106. The absorption of fats and carbohydrates is reduced by delaying themixing of bile with the chyme.

The sleeve 202 provides weight loss mechanisms by providing negativefeedback, reduced fat digestion and reduced desire for food. The reducedfat digestion occurs because the sleeve 202 delays the mixing of bileand pancreatic juices with chyme from the stomach until after the chymeleaves the sleeve 202. The reduced desire for food may occur because thesleeve 202 blocks hormonal release from the duodenum 104. Additionally,providing poorly digested food to distal portions of the intestine, suchas to the ileum, can trigger hormones that reduce appetite.

The sleeve 202 is non-compliant and drapes away from the intestinalwalls thereby permitting the pancreatic juice to flow unimpeded into theduodenum 104 through the papilla of Vater 114. The normal peristalsis ofthe bowel is used to propel the chyme, bile, and pancreatic juicesthrough the intestines.

FIG. 6 is a perspective view of a collapsible self-expanding anchor 600in the gastrointestinal implant device 200 shown in FIG. 2 whenexpanded. The anchor 600 is non-woven, collapsible and self-expanding,allowing catheter-based insertion and removal of the implant device 200.The anchor 600 includes a plurality of flat struts 602 forming an openspace pattern to ease collapsing while ensuring self-expansion. The openspace pattern allows for collapsing into a catheter for endoluminaldelivery and removal. The struts 602 may be manufactured from aresilient metal such as a heat-treated spring steel, or from an alloysuch as NiTi alloy commonly referred to as Nitinol. Other alloys includenickel-cobalt-chromium-molybdenum alloys possessing a unique combinationof ultrahigh tensile strength, such as MP35N, available from AsahiIntecc Co., Ltd. of Newport Beach, Calif.

In the embodiment shown, the anchor has a length L of about 1.5 inchesand has a diameter D of about 1.5 inches. The struts 602 are flat, about0.010 inches wide and about 0.004 to 0.010 inches thick. The anchor canbe formed from a tube of material by laser cutting followed by expansionand heat setting, or other methods well known to those skilled in theart.

In an alternate embodiment, the struts 602 can be formed separately andthe strut intersections can be welded or attached by other means wellknown to those skilled in the art. Visually the struts form sections 604around the circumference of the anchor. Each section has a series oftriangles with each triangle defined by one distal strut connection 606and two proximal strut connections 608, 610. The ratio of the collapseddiameter to the expanded diameter of the anchor is roughly 1:4.

When expanded, the angle α between divergent strut sections is about45-50 degrees and the diameter of the anchor is about 1.5 inches. Whencompressed, the angle β between divergent strut sections is about 5-6degrees to reduce the diameter of the anchor to about 0.5 inches forcatheter-based delivery and removal. The elasticity of the strutspermits this compression. When the radial compression is released, theelasticity of the struts causes the anchor to expand to diameter D. Theanchor assumes its desired diameter as the elastic restoring forces seektheir minimum stress.

In some embodiments, the ends of the struts at the proximal end of theanchor 600 can be elongated and shaped to provide barbs 612 to anchor tothe muscular tissue of the duodenum 104.

FIG. 7 is a perspective view of the anchor 600 shown in FIG. 6 whencompressed. The anchor 600 is compressed until the angle β betweendivergent strut sections is about 5-6 degrees to reduce the diameter Dof the anchor 600 to about 0.5 inches for catheter-based delivery andremoval. The barbs 704 at the proximal end of the anchor are elongated.The barbs 704 can be shaped to anchor the anchor to the muscular tissueof the duodenum 104.

FIG. 8 is a perspective view of another embodiment of a anchor 800 whencompressed. Pairs of barbs 802 at the proximal end of the anchor 800 areelongated and can be shaped to provide opposed barbs to anchor theanchor 800 in the muscular tissue of the duodenum 104.

FIG. 9 is a perspective view of the compressed anchor 800 shown in FIG.8 with the strut ends 902, 900 bent to provide opposed barbs 904, 906.The barbs 904,906 engage the muscular tissue of the duodenum 104 toanchor the gastrointestinal implant device in the muscular tissue of theduodenum 104. As shown in FIG. 2, the strut ends 900, 902 protrudeoutward from the outer surface of the anchor 800 in opposite directions.They may be perpendicular to each other. The barbs 904, 906 at the endsof the respective opposed strut ends 900, 902 dig into the surroundingmuscular tissue to secure the anchor. The barbs 904, 906 at the end ofthe protruding opposed strut ends 900, 902 prevent movement of theanchor 800 in either direction; that is, they prevent movement of theanchor 800 into the stomach 102 and prevent movement of the anchor 800down through the duodenum 104.

FIG. 10 is a perspective view of the anchor 800 shown in FIG. 8 whenexpanded. As discussed in conjunction with FIG. 9, the opposed strutends 904, 906 engage the muscular tissue of the duodenum 104 while theanchor 800 is expanded. In the engaged position, the barbs 904, 906spread radially outward from the longitudinal axis of the anchor 800such that the tips of the barbs come into contact and engage the tissue.

FIG. 11 illustrates the gastrointestinal device 1100 shown in FIG. 1including an anti-buckling mechanism 1102. A flexible, anti-rotation,anti-buckling mechanism 1102 is attached to the sleeve 202 and extendsfrom below the distal end of the anchor along the length L of the sleeveto the distal end of the sleeve 202. In the embodiment shown, theanti-buckling mechanism 1102 is a guidewire device attached to theexterior surface of the outer layer of the flexible sleeve. Guidewiredevices are well known to those skilled in the art. A first proximal endof the guidewire device 1104 is attached below the anchor and a seconddistal end of the guidewire device 1106 is attached to the distal end ofthe flexible sleeve. The diameter of the guidewire ranges from about0.010 to about 0.016 inches.

The gastrointestinal implant device 200 is designed for catheter-basedplacement (e.g., endoluminal). FIG. 12 is a perspective view of aportion of a catheter system 1200 for delivery of the gastrointestinalimplant device. The catheter system follows a guide wire 1212 through anatural lumen such as the esophagus and the stomach 102 and through thepylorus 108 itself. The guide wire 1212 enters a first inner lumen atthe proximal end 1208 of the catheter system 1200 and exits the firstinner lumen at the distal end 1222 of the catheter system 1200.

The catheter system 1200 includes an outer sheath 1202 for storing theanchor 208 in collapsed form, a flange 1216 to pull back the outersheath 1202 and a sleeve retention wire mechanism 1224 for releasing asleeve retention wire 1210 from the proximal end of the flexible sleeve202 after the anchor has been released from the outer sheath 1202.

As described in conjunction with FIG. 2, the distal portion of thegastrointestinal implant device includes an unsupported flexible sleeve202 which can negotiate the duodenum and the jejunum. A sleeve retentionwire 1210 travels through a second inner lumen and exits the secondinner lumen to secure the distal end of the sleeve 202 to an innersheath 1226. The sleeve retention wire 1210 is coupled to the sleeveretention wire release mechanism 1224 for releasing the sleeve retentionwire 1210 after the gastrointestinal implant device has been positionedin the duodenum 104. The release mechanism 1224 will be described laterin conjunction with FIG. 16B.

The sleeve 202 is secured temporarily outside the inner sheath 1226allowing for proper positioning of the gastrointestinal implant deviceand then for release. As shown, the sleeve 202 is secured by the sleeveretention wire 1210 using a dead-bolt mechanism 1206. Non-stick coatingssuch as Teflon on the sleeve retention wire 1210 are preferred to makerelease easier to accommodate tortuous anatomical pathways. The sleeveretention wire 1210 extends through the second inner lumen from therelease mechanism 1224 of the catheter system 1200 to the dead-boltmechanism 1206. The dead-bolt mechanism 1206 is described later inconjunction with FIG. 14A. The sleeve retention wire 1210 holds thesleeve in position. The distal end of the folded sleeve is released bythe release mechanism 1224 by pulling the sleeve retention wire 1210backward from the proximal end 1208 of the catheter.

As described in conjunction with FIG. 2, the proximal portion of thegastrointestinal device includes a covered anchor. The anchor in thegastrointestinal implant device is collapsed and stored in the outerlumen within the outer sheath 1202 between the flange 1216 and theproximal end 1208 of the outer sheath 1202. The anchor is supported in acollapsed form by the outer sheath 1202. The catheter 1200 is insertedinto the digestive system through the esophagus through the pyloricsection of the stomach. The proximal end of the outer sheath 1202 ispositioned in the duodenum through the use of positioning ring 1240.After the outer sheath 1202 has been positioned, the anchor is retractedfrom the outer lumen of the catheter by pulling flange 1216 toward theproximal end of the catheter system 1200. Upon release, the anchorself-expands by its own elastic restoring force to engage the anchorportion with the surrounding muscular tissue of the duodenum.

FIG. 13 is a cross-sectional view of the inner shaft 1226 taken alongline E-E of FIG. 12. The sleeve retention wire 1210 passes through asecond inner lumen 1314 in the inner sheath 1226. The sleeve retentionwire 1210 exits the second inner lumen 1314 and is threaded throughfolds of the sleeve 202 at 1302 in FIG. 14A. The sleeve retention wire1210 re-enters the second inner lumen 1314 at 1302 (FIG. 14A). Theguidewire 1212 passes through the first inner lumen 1310.

FIG. 14A is an expanded perspective view of the dead-bolt mechanism 1206shown in FIG. 12. The sleeve 202 has been folded for delivery. Thesleeve 202 is wrapped around the inner sheath 1226 and bunched above theinner sheath 1226. The sleeve 202 is held in folded position around theinner sheath 1226 by threading the sleeve retention wire 1210 throughthe folds of the sleeve 202. The sleeve retention wire 1210 exits thesecond inner lumen 1314 through an opening 1304 and pierces throughfolds of the sleeve 202 at 1304. Threading the sleeve retention wire1210 through the folds of the sleeve 202 results in a plurality of smallholes at the distal end of the sleeve 202. The holes are reinforced withsilicone or urethane to avoid tears in the material. The sleeveretention wire 1210 re-enters the second inner lumen through a secondhole 1302 and advances a sufficient distance within the second innerlumen toward the distal end of the second inner lumen to resist pullingout of the second inner lumen.

FIG. 14B is a sectional view of the dead-bolt mechanism 1206 shown inFIG. 14A illustrating the sleeve retention wire 1210 threaded throughthe sleeve 202. The sleeve retention wire 1210 exits the second innerlumen at 1306 and pierces through folds in the sleeve 202 at 104. Thesleeve retention wire 1210 re-enters the second inner lumen at 1302.

FIG. 15 is a sectional view of a portion of the catheter system shown inFIG. 12 illustrating the collapsed anchor 208 stored inside the outersheath 1202. The anchor 208 is pre-compressed and held in a collapsedform inside the outer sheath 1202 of the catheter. The outer sheath 1202is pulled back by the flange 1216 toward the proximal end of thecatheter system 1200 to release the self-expanding anchor 208. Theanchor 208 radially expands under its own elastic restoring force. Theguidewire 1212 is directed through the first inner lumen and the sleeveretention wire 1210 is directed through the second inner lumen in theinner sheath 1226. The inner sheath 1226 includes a first lumen throughwhich the guidewire 1212 passes and a second lumen through which thesleeve retention wire 1210 passes.

FIGS. 16A-C illustrate a method for delivery of the gastrointestinalimplant device. FIG. 16A is a plan view of the catheter system 1200illustrating the collapsed anchor 208 stored inside the outer sheath1202 of the gastrointestinal implant device. As described in conjunctionwith FIG. 12, the anchor 208 is stored inside the outer sheath and thedistal end of the sleeve 202 is secured outside the inner sheath 1226 bya sleeve retention wire 1210.

FIG. 16B is a plan view of the catheter system illustrating thegastrointestinal implant device 200 after release of the anchor from theouter sheath. The flange 1216 has been pulled back toward the proximalend of the catheter system 1200 to pull back the outer sheath 1202 fromthe anchor 208 and the anchor 208 has self-expanded. The sleeveretention wire 1210 holds the distal end of the sleeve 202.

Once in place, the sleeve retention wire 1210 can be removed. Asdescribed previously in conjunction with FIG. 12, the sleeve retention1210 is coupled to locking mechanism 1224. The handle 1600 in thelocking mechanism 1224 acts as a pivot device to pull the sleeveretention wire 1210 from the dead-bolt mechanism 1206. The distal end ofthe gastrointestinal implant device 200 is released by moving handle1600 in a clockwise direction 1604. As the handle 1600 is moved indirection 1604, the sleeve retention wire 1210 threaded through thefolds of the sleeve is pulled back through the second inner lumen 1314and disengages from the sleeve 202 at the distal end of thegastrointestinal implant device 200. The sleeve retention wire 1206extends from the distal end of the gastrointestinal implant device 200through the second inner lumen 1314. The wire is connected to the handle1600 at the proximal end of the catheter.

FIG. 16C is a plan view of the catheter system 1200 illustrating theexpanded gastrointestinal implant device 200 after the sleeve retentionwire 1210 has been released. The handle 1600 has been moved in aclockwise direction and the sleeve retention wire 1210 pulled backthrough the second inner lumen 1314 to release the distal end of thesleeve 202.

FIG. 17 is a perspective view of another embodiment of the cathetersystem 1200 shown in FIG. 16. The catheter includes a ball 1800 coupledto the distal end 1222 of the inner sheath 1226 for guiding the catheterthrough the alimentary canal to beyond the pyloric portion of thestomach 102. The ball 1800 is small enough so that it can be pulled backthrough the gastrointestinal implant device after the gastrointestinaldevice 200 has been delivered, the anchor expanded and the sleeveretention wire 1210 has been released. The sleeve 1204 is shownuniformly folded. However, the sleeve 1204 may not necessarily beuniformly folded.

FIG. 18 is a cross-section of an everting catheter system 1900 fordelivery of a longer unsupported flexible sleeve 1902. Thegastrointestinal implant device 200 is shown with the sleeve anchor 1901and the attached sleeve 1902 shown as delivered into the anatomy. Thedelivery catheter previously described is then removed. A ballooncatheter 1906 is introduced into the sleeve anchor 1901 and the balloon1908 inflated to seal the lumen of the anchor 1901. The sleeve 1902 isfolded inside itself and an elastic band 1912 is used to seal the end ofthe sleeve. Fluid is then injected through the balloon catheter shaft1906 into the sleeve lumen 1910, filling the lumen and pressurizing it.The pressure of the fluid is used to push the inner sleeve distallytowards 1904. When the sleeve 1902 has fully deployed distally, theelastic band 1912 falls off of the closed end of the sleeve 1902 andpasses distally in the intestine until it is excreted. This mechanismpermits deployment of a sleeve that is longer than (e.g., double) thelength of the delivered device. This may be needed as it is difficult toaccess the distal parts of the intestine with guidewires. This evertingcatheter system 1900 enables delivery of longer sleeves than arepossible using only the delivery catheter described in conjunction withFIG. 12.

FIG. 19 is a perspective view of a retrieval device 2000 for removingthe gastrointestinal implant device 200 from the digestive tract. Asalready described, the exterior surface of the anchor 208 can be coveredwith a material that prevents cellular in-growth allowing the anchor 208to be easily removed. The retrieval device 2000 includes an inner sheath2004 and an outer sheath 2006. A plurality of fingers 2002 extend fromthe proximal end of the inner sheath 2004. The fingers 2002 engage theexterior surface of the gastrointestinal device. As the inner sheath2004 is moved down over the fingers, the fingers 2002 pull radiallyinward to reduce the proximal anchor diameter and pull the collapseddevice into the outer sheath 2006.

FIG. 20 is a perspective view of the retrieval device 2000 engaged withthe anchor 208. The fingers 2002 of the retrieval device are positionedaround the anchor 208. As the inner sheath 2004 is pushed over thefingers 2002, the fingers pull radially inward on the proximal end ofthe anchor 208 and the proximal end of the anchor 208 is collapsed.After the anchor 208 has been collapsed sufficiently such that theproximal anchor diameter is less than the diameter of the outer sheath2006, the anchor is drawn into the outer sheath 2006. The entiregastrointestinal implant device can then easily be removed from thepatient by pulling retrieval device 2000 through the stomach and theesophagus.

In another embodiment, the anchor 208 can be configured with adrawstring. The drawstring can be selectively woven around the perimeterof the anchor 208 through openings of opportunity in the anchor 208. Theopenings can be defined by adjacent interconnected struts of the anchor208. Alternatively, or in addition the drawstring can be selectivelywoven through dedicated openings, such as eyelets provided on the anchor208. In some embodiments, the drawstring is woven through openings atthe proximal end of the anchor 208. In operation, the drawstring can bepulled in a proximal direction by a retrieval device. The drawstring,when pulled, contracts about the perimeter of the anchor 208, therebyreducing the diameter of the anchor 208. Thus, the drawstring can beused to facilitate removal of an implanted anchor 208 by pulling it awayfrom the surrounding anatomy thereby extracting any barbs from thesurrounding muscular tissue.

FIG. 21 is a perspective view of another embodiment of agastrointestinal implant device 2200. The gastrointestinal implantdevice 2200 includes a sleeve 202 and an anchoring ring 2204. The distalend of the anchoring ring 2204 is bonded to the proximal end of thesleeve 202. A plurality of eyelets 2206 are distributed around thecircumference of the proximal end of the ring for anchoring the deviceto the muscular tissue of the duodenum 104 using anchors shown in FIG.24. The anchoring ring 2204 is made from a flexible, biocompatiblematerial such as silicone allowing the ring 2204 to be collapsed forcatheter-based insertion and removal. Preferably, the anchoring ring2204 does not interfere with the normal opening and closing of thepylorus 108.

FIG. 22 is a perspective view of the anchoring ring 2204 shown in FIG.21 in the expanded position. The sleeve 202 is bonded to the outersurface 2300 of the proximal end of the anchoring ring 2204 whosediameter is 1 inch or about the same as the diameter of the sleeve 202.The anchoring ring 2204 includes at least four eyelets 2206 to anchorthe device 2200 in place. The outer most diameter of the ring 2204 isabout one inch. In an alternate embodiment there can be more than foureyelets 2206.

FIG. 23 is a perspective view of the anchoring ring 2204 shown in FIG.21 in a collapsed position for insertion and removal. The circular ring2204 shown in FIG. 21 has been compressed to an oval shape allowing theanchoring ring to be inserted into the lumen of a catheter for delivery.

FIG. 24 is a perspective view of an anchor 2500 for anchoring thecollapsible ring shown in FIG. 23 to the muscular tissue of the duodenum104. The anchor 2500 includes an anchor pin 2504 coupled to a second pin2506 by a flexible shaft 2502. The anchor pin 2504 includes a shapedbarb 2508 for locking the anchor 2500 into the tissue. The anchor 2500is delivered after the collapsible ring has been positioned in theduodenum 104. The anchor 2500 is guided so that the anchor pin 2504 isdirected through a respective eyelet 2206 with the barbed portion of theanchor pin 2504 guided toward the tissue. After the barb 2508 has beenlocked into the tissue, the second pin 2506 sits inside thegastrointestinal implant device while the barbed portion 2508 of theanchor pin 2504 sits inside the muscular tissue of the duodenum 104. Forremoval of the gastrointestinal implant device from the body, theflexible shaft 2502 of the anchor 2500 is cut.

FIG. 25A is a perspective view of a delivery system 2600 for deliveringthe anchor 2500 after the gastrointestinal implant device has beenplaced in the duodenum 104. The anchor 2500 is loaded in the distal endof a catheter having a single lumen tube 2600. The hollow, distal end ofthe delivery device 2600 is a sharp needle made to penetrate themuscular tissue of the duodenum 104. In an alternate embodiment, thedistal end of the delivery device 2600 can be formed in an arc toimprove access to the eyelets 2206 through an endoluminal approach. Thecatheter 2600 includes a pusher 2604 for releasing the anchor 2500. Thepusher 2504 is moved in a longitudinal direction 2602 to release theanchor 2500 from the lumen.

FIG. 25B is a plan view of the delivery system 2600 shown in FIG. 25A.FIG. 25C is a cross-sectional view of the distal end of the catheter2600 as taken along line B-B of FIG. 25B. As described in conjunctionwith FIG. 24, the anchor 2500 includes pins 2504, 2506 coupled by aflexible shaft 2502. The anchor 2500 is loaded in the lumen at thedistal end of the catheter 2600. The anchor pin 2504 is placed in thedistal end of the tube 2600 and the second pin 2506 in the proximal end.The barb 2508 on the anchor pin 2504 is pointed toward the proximal endof the tube 2506 to engage with the tissue upon release in the muscletissue. The catheter 2600 is advanced to the center of the ringpositioned in the duodenum 104. The sharp end 2510 is then pushedthrough an eyelet 2206 and into the surrounding muscular tissue. Thepusher 2506 is pushed in longitudinal direction 2602 to release thedistal anchor 2506. Once the distal anchor 2506 is released, thedelivery system 2600 is pulled back, dragging the proximal part of theanchor out of the delivery device with the flexible shaft going throughthe eyelet 2206, and the proximal anchor portion resting on the insideof the device. In the embodiment of the ring shown in FIG. 22, fouranchors 2506 are delivered to anchor the gastrointestinal implant devicethrough the four eyelets.

FIG. 25D is an isometric view illustrating the sharp end 2510 of theneedle inserted through an eyelet 2206 for delivery of the anchor 2500to the tissue 2512. The distal end of the catheter is formed in an arc2520 to improve access the eyelets 2206. The sharp end 2510 of thecatheter is inserted through the eyelet 2206 into the tissue 2516. Theanchor pin 2504 of the anchor has been pushed out from the lumen intothe tissue 2512.

FIG. 25E is an isometric view illustrating the barb 2508 engaging thetissue 2512 after delivery. The catheter has been removed from theeyelet 2206 leaving the anchor pin 2504 engaging the tissue 2516.

FIGS. 26A-E illustrate an alternative embodiment of a locking mechanismfor holding the distal end of the sleeve 202 in position during deliveryof the gastrointestinal implant device 200. The snare wire 2656 ispassed through one of the lumens of the catheter 2650 to the distal end.At the distal end, the end of the snare wire 2656 is looped back andattached to or anchored inside the catheter 2650. The folds of thesleeve 202 are advanced through this snare loop. The snare handle 2664pulls and releases the snare wire 2656 to lock and release the distalend of the sleeve 202. The delivery system 2600 includes a pull tap 2666for releasing a drawstring holding the anchor in a collapsed position.

FIG. 26B is cross-sectional view taken along line C-C of FIG. 26Athrough the inner sheath 2650. The inner sheath 2650 has two lumens2654, 2656 and has a diameter of about 0.078 inches. The first innerlumen 2564 is for passing a guidewire through the inner sheath and isabout 0.04 inches in diameter. The second inner lumen 2656 is forpassing the snare wire 2656 through the inner sheath 2650 is about 0.02inches in diameter. The end of the snare wire 2658 is anchored insidethe inner sheath 2650.

FIG. 26C is a cross-sectional view taken along line DD of FIG. 26Athrough the outer sheath 2600 showing the inner sheath 2650 within theouter sheath 2600. The outer sheath 2600 has an inner diameter of about0.1 inches and an outer diameter of about 0.143 inches. The open spaceinside the outer sheath 2600 can be used for passing a drawstringthrough the outer sheath 2600.

FIG. 26D is a cross-sectional view through the distal portion of thecatheter showing the snare 2656 capturing the distal end of the sleeve202. The distal end of the sleeve 202 is captured by the snare wire 2656by pulling the distal end of the sleeve 202 through a loop formed by thesnare wire 2656.

FIG. 26E is a sectional view through the distal portion of the cathetershowing the snare locking mechanism. The distal end of the sleeve 202 islocked by pulling the snare wire 2656 in a longitudinal direction 2664toward the proximal end of the delivery system to capture the sleevefolds against the inner shaft. After the gastrointestinal implant device200 is properly positioned in the body, the snare wire 2656 is advancedin a longitudinal direction 2662 toward the distal end of the deliverysystem. This opens the snare wire 2656 and releases the sleeve 202.

FIG. 27 is a perspective view of the distal portion of an embodiment ofthe gastrointestinal implant device including texturing 2700. Texturingof the distal end of the sleeve 202 can be added to ensure that theactions of peristalsis do not advance the sleeve 202 proximally, towardsthe stomach 102, but keep the sleeve 202 pulled taught in the intestine112. At the distal end of the sleeve 202, texturing 2700 is added with adirectional aspect to it. The texturing 2700 can be molded into thesleeve material or added by adhesive or thermal bonding methods. Thetexturing material contains fibril shapes that are directed proximallyso that any peristaltic waves that travel proximally, will have lessforce on the sleeve than distal peristaltic waves.

The gastrointestinal implant device offers a new alternative where othermeans of weight loss and efforts at behavior modification have failed.Because the gastrointestinal implant device is introduced through asmall diameter catheter (e.g., endoluminally), there is a reduced riskat insertion compared to surgery. The procedure is also completelyreversible, making this approach the ideal solution for patients who aredesperate to reverse behavioral patterns that have lead to weight gain.

When inserted in the body, the gastrointestinal implant device mimicsthe duodenal bypass of the Roux-en-Y procedure. The implanted devicereduces caloric absorption by delaying enzyme mixing with food andprovides the feedback produced by the Roux-en-Y procedure by producingdumping syndrome when high sugar meals are ingested. The implant deviceis an improvement on the Roux-en-Y procedure because it is minimallyinvasive and reversible. In the treatment of the super-obese whereaggressive weight loss is not achieved, the length of the implant devicebelow the anchor can be further increased to drive the patient close tothe point of malabsorption.

Placement of the gastrointestinal implant device effectively providesthat ingested food does not digest in a normal manner and the guthormones that are normally triggered are modified. These hormones resultin several physiology changes that impact hunger and digestion. Guthormones include peptide YY (PYY), cholecystokinin (CCK) and ghrelin.

As under digested food enters the ileum or distal part of the smallintestine 112, a hormone called peptide YY or PYY is released. Thishormone has been shown to have a direct effect on appetite, reducing itwhen released. Undigested food in the ileum indicates that too much foodhas been ingested. Thus, dependent on the length of the sleeve, thegastrointestinal device can promote deposition of undigested orpartially digested food to the distal bowel. Therefore, the placement ofa sleeve in the intestine promotes the delivery of undigested food tothe ileum, which in turn promotes the release of PYY and reducesappetite in humans.

The hormone cholecystokinin (CCK) is released when food contacts theduodenum 104. CCK triggers the release of bile from the gallbladder.Therefore, placing a sleeve in the duodenum 104 reduces the release ofCCK and thus reduces bile output resulting in reduction in the digestionof food.

Some ghrelin is released when food contacts the duodenum 104. Ghrelinhas been shown to be a factor in the control of appetite. This devicewill reduce ghrelin output and thereby reduce appetite due to the bypassof the duodenum 104.

Type-2 diabetes is a disease of obesity that occurs when patients cannotadequately use the insulin they produce. Usually, it is not that thepatient cannot make enough insulin, but rather that the patient's bodycannot effectively use the insulin produced. A particularly dangerousresult of Type-2 diabetes is that blood sugar spikes after a meal. Thisis called post-prandial hyperglycemia. This spike in blood glucosecauses cardiovascular and microvascular damage. One class of drugs usedto control post-prandial hyperglycemia is the alpha-glucosidaseinhibitors. These work by reducing the breakdown and absorption ofcarbohydrates to sugars. The sleeve has a similar function because itreduces bile and delays the breakdown and absorption of thecarbohydrates, which are normally readily absorbed in the duodenum, butare less likely to be absorbed in the jejunum and ileum. Therefore, type2 diabetes can be controlled by placing a sleeve in the proximalintestine to delay the digestion of carbohydrates which reducespost-prandial hyperglycemia.

The gastrointestinal implant device can be used to reduce Type-2diabetes symptoms by bypassing the duodenum 104. Following gastricbypass surgery, patients commonly experience complete reversal of Type-2diabetes. While the exact mechanism of this remarkable effect is notunderstood, the clinical result is reported in a high percentage ofcases. Reversal of Type-2 diabetes after gastric bypass is described in“Potential of Surgery for Curing Type-2 Diabetes Mellitus” by Rubino etal. incorporated herein by reference in its entirety. Since thegastrointestinal implant device provides equivalent blockage of duodenalprocesses, a similar effect is elicited but without the trauma ofsurgery. In patients who are not obese but suffer Type-2 diabetes, amodified gastrointestinal implant device is inserted. Thisgastrointestinal implant device provides the necessary effect to hinderpancreatic processes and receptors without blocking absorption.

In the embodiment of the gastrointestinal implant device for treatingdiabetes, placement of the anchor within the stomach and/or duodenumallows the pylorus 108 to operate normally. The length of the sleeve maybe reduced to mimic the duodenum bypass. The sleeve extends to justbelow the ligament of Treitz 118 but may not extend further into thejejunum 106, thus allowing absorption to occur in the jejunum 106.

The gastrointestinal implant device can be placed temporarily in theduodenum 104 to allow tissues to heal. For example, the sleeve can beplaced temporarily to promote healing of ulcers in the duodenum 104.Ulcers are lesions that form in tissues of the duodenum 104. If theybleed, they are typically cauterized with electrosurgery. For ulcers toheal, they must be protected from the acidic environment. Placement of asleeve for a short time period, for example, for one to two weeks,promotes healing of ulcers in the duodenum 104 by eliminating the acidicenvironment and allows the tissues to heal.

Intestinal anastomoses are performed to remove sections of diseasedbowel. The stapled or sewn connection is prone to leakage until itheals. The placement of the gastrointestinal implant device temporarilyin the bowel can be used to promote healing of small bowel anastomosesby protecting the area from chyme and minimizing leaks.

The gastrointestinal implant device can be used to deliver drugs,hormones and other active agents directly to the intestine. To deliverthe agents, the sleeve and/or anchor is either coated or impregnatedwith the agents. The agents can include anti-inflammatory agents toreduce irritation due to placement of the anchor within the body. Theagents can optionally or in addition include anti-hunger hormones.

The two most common intestinal bowel diseases are Crohn's disease andUlcerative Colitus. Crohn's disease may occur in any part of thedigestive tract. Although the exact cause of the disease is unknown, itappears to be an abnormal immune response in the patient, which leads tochronic inflammation of the intestinal lining.

Crohn's disease is treated with drugs intended to reduce inflammation.These include aminosalicylates, corticosteroids, immune modifiers suchas azathioprine and methotrexate and antibiotics including ampicillinand cipro. These drugs have negative effects when given systemically.Since the drug is really only needed locally, smaller amounts of drugcan be used if delivered directly to the tissues. Thus, an implantedsleeve treated with such a drug advantageously treats the surroundingtissues.

The intestinal sleeve can be coated with polymers that are impregnatedwith these drugs. Coatings may include polyurethanes, silicones andhydrophilic polymers such as those available from Hydromer ofSomerville, N.J. These coatings may be applied to the sleeve material bydipping or spraying techniques. If a porous sleeve material such asePTFE is used, the drug-filled polymer may be driven into the poresusing pressure applied to the sleeve, such as internal pressure insidethe sleeve. This increases the amount of drug that is available.

The sleeve material can also be a polymer that permits the incorporationof the drug directly into the wall. Such polymers include Ethylene VinylAcetate (EVA) and polyurethane. A greater amount of the drug may beincorporated in this case compared to a coating since there is morematerial in the wall than simply in coatings, thereby providing longerrelease times. The drug is compounded into the polymer and then extrudedas is normally done to form the tubing or sheet from which the sleeve ismade.

The sleeve is deployed transesophageally into the duodenum 104 andproximal jejunum 106. When the sleeve comes in contact with the tissues,the drugs in the coating are released directly into the tissues. Also,the sleeve may act to block the contact of the food to the mucosa,thereby reducing irritation caused by the chyme. Once the drug has fullyeluted from the material, the sleeve is removed and a new one is placed.

The control of appetite in the human is a complex function of hormonalinteractions. Several hormones have been implicated in its controlincluding Ghrelin, Peptide YY, Leptin, Glucagon-Like Peptide-1 (GLP-1),Cholecystokinin (CCK), insulin and others. These hormones are eitherreleased or suppressed by the presence of food in the duodenum. Forexample, PYY acts as an anti-hunger hormone as injections of PYY havebeen shown to decrease food intake in both rats and humans and decreasesin leptin have been shown to stimulate hunger.

Sleeves that are located in the duodenum 104 where many of thesehormones are released may be impregnated with these hormones. Whenimplanted, the hormones elute from the sleeve into the surroundingtissue where they activate the various satiety mechanisms.

FIG. 28 is a perspective view of a gastrointestinal implant device withanother embodiment of a collapsible self-expanding anchoring device. Thegastrointestinal implant device 2800 includes a sleeve 202 and ananchoring device 2810 for anchoring the gastrointestinal implant 2800device in the duodenum 104. The anchoring device 2800 includes a waveanchor 2810 coupled to a proximal portion of the sleeve 202. Referringto FIG. 29, the wave anchor 2810 includes a compliant, radial spring2900 shaped into an annular wave pattern about a central axis 2910,providing an outward radial force, while allowing substantial flexureabout its perimeter. Such flexure is advantageous as it allows forminimally-invasive delivery and ensures that the device willsubstantially conform to the surrounding anatomical structure whenimplanted. The annular wave element 2900 can be formed from one or moreelongated resilient members and defines a lumen along its central axisformed between two open ends. When implanted, as shown in FIG. 30, thecentral axis of the anchor 2810 is substantially aligned with thecentral axis of the duodenum 104, allowing chyme to pass through thedevice 2800. Additionally, the compliant wave anchor 2810 minimizestrauma to the tissue by providing sufficient flexibility and compliance,while minimizing the likelihood of tissue erosion and providing a solidanchoring point to the tissue.

The compliant wave anchor 2810 can be manufactured from a resilientmetal such as a heat-treated spring steel, stainless steel, or from analloy such as NiTi alloy commonly referred to as Nitinol. Other alloysinclude nickel-cobalt-chromium-molybdenum alloys possessing a uniquecombination of ultrahigh tensile strength, such as MP35N. Additionally,the wave anchor 2810 can be formed from a polymer and/or a compositehaving similar properties. The wave anchor 2810 can be manufactured froma single strand, such as a wire, contoured into the desired shape.Alternatively, the wave anchor 2810 can be manufactured frommulti-strands of the same or different materials similarly contoured tothe desired shape. In some embodiments, the wave anchor 2810 can be cutinto the wave shape from tubular stock of the desired material, such asNitinol.

The anchor 2810 can be removably attached within the body using any ofthe methods described herein for securing a anchor 208, including theuse of barbs attached to, and/or formed on the anchor itself. Whenimplanted, the anchor 2810 enables a sleeve 202, or barrier to besecurely implanted within the duodenum 104, preferably providing a fluidseal at the proximal end. To enhance a fluid seal, the proximal end ofthe sleeve can be contoured to the wave anchor as shown in FIG. 31. Fora device 2800 using a sleeve 202 contoured to the wave anchor 2810,proximal end appears tulip-shaped.

FIG. 32A is a perspective view of a portion of a low profile cathetersystem 4250 for delivery of a gastrointestinal implant device. The lowprofile catheter has a detachable generally spherical shaped element4218 coupled to the distal end of an inner shaft 4200 to aid thedelivery of the catheter through the alimentary canal into theintestines. After the gastrointestinal implant device has beendelivered, the spherical shaped element (ball) 4218 is detached and thezero profile catheter is removed through the gastrointestinal implantdevice. The normal peristalsis of the bowel is used to move the releasedball through the intestines.

The catheter system 4250 includes an outer sheath 4222 for storing thecollapsible anchor portion of the gastrointestinal implant device incollapsed form. Collapsible anchoring devices have already beendescribed in conjunction with FIGS. 7, 23 and 28-31. The sleeve 202 issecured temporarily outside an inner sheath 4200 allowing for properpositioning of the gastrointestinal implant device and then for release.

FIG. 32B is a cross-sectional view of the inner shaft 4200 of thecatheter system as taken along line 42B-42B of FIG. 32A. In oneembodiment, the inner shaft 4200 is a three-lumen extrusion of Pebax7233 with an outer diameter of 0.080 inch and round inner lumens 4202,4204, 4206 having respective diameters of 0.040, 0.020, and 0.020inches. This material is selected to maintain a low profile, a smallminimum bend radius; that is less than 0.5 inch without kinking, goodcolumn strength when fortified with an inner guide wire stylet, and alow coefficient of friction in a material with good thermoplastic andbonding properties.

A first lumen 4202 is used to pass a guide wire or mandrel 4226 throughthe catheter shaft to increase the rigidity of the catheter shaft duringintroduction of the catheter into the intestines. The first lumen 4202is also used to inject fluid to lift the sleeve material 202 away fromthe inner shaft 4200 after the gastrointestinal device has beendelivered to the intestine. A second lumen 4204 is used to pass a sleeveretention wire 4208 to the distal end of the gastrointestinal implantdevice. The sleeve retention wire is used to hold the distal end of thesleeve 202 to the outside of the inner shaft 4200. A third lumen 4206 isused to inject fluid at the tip of the catheter to lift the distal endof the sleeve 202 off the inner shaft 4200 prior to removal of thecatheter system 4250 from the body.

Returning to FIG. 32A, the guide wire 4226 is passed through fitting4210 connected to the first lumen 4202. The sleeve 202 is locatedconcentrically over the catheter inner shaft 4200. It is held at itsdistal end to the inner shaft 4200 with the sleeve retention wire 4208.The sleeve retention wire 4208 holds the sleeve 202 in place duringdelivery.

Proximal fitting 4220 is connected to the second lumen and proximalfitting 4212 is connected to the third lumen 4206. During delivery ofthe gastrointestinal implant device, the first lumen 4202 is filled witha 0.035 inch Teflon coated guide wire 4226 that provides column strengthfor the appropriate amount of pushability without compromising theflexibility of the catheter inner shaft 4200. A 0.015 inch diameterTeflon-coated steel wire is placed in the second lumen 4204 to serve asthe distal sleeve retention wire. The second lumen 4204 has 2 skiveholes 4214, 4216 near the distal end of the catheter shaft 4200. Thedistal sleeve retention wire 4208 exits the second lumen 4204 through aproximal skive hole 4214 feeds through the sleeve material 202, which iswrapped tightly around the distal outer diameter of the catheter shaft,and re-enters the second lumen 4204 through a distal skive hole 4216.This creates a dead bolt style lock holding the sleeve 202 to the shaft4200 until ready to be released similar to the dead bolt style lockdescribed in conjunction with the two lumen catheter shaft shown inFIGS. 14A and 14B.

The distal end of the shaft terminates with a spherical shaped element4218 that is either solid, or inflatable to form an atraumatic tip. Inthe embodiment shown, the spherical shaped element is a solid ball,similar to the ball described in conjunction with FIG. 17. In theembodiment shown, the diameter of the ball is about 0.5 inch (12.7 mm),however the range of diameters is about 0.25 inch (6.4 mm) to about 0.75inch (19.2 mm). An embodiment of an inflatable spherical shaped elementis described later in conjunction with FIGS. 40A-40B. The ball 4218 atthe end of the catheter shaft is held onto the shaft 4200 with thesleeve retention wire 4208 maintaining tension on the ball 4302 whichwill be described later in conjunction with FIG. 36.

The collapsed anchor assembly is located in outer sheath 4222. The ball4218 at the end of the catheter is released to withdraw the catheter.The release mechanism pulls the sleeve retention wire to release theball end and release the end of the sleeve. The anchor assembly is thenreleased from the outer sheath as previously described

The catheter can be used any time access to the intestinal tract isdesired. For example, the catheter can be used to pass an endoscope intothe intestine. This catheter device can be used to rapidly run theintestines, place a guide wire and then use the placed guide wire as atrack for an endoscope.

FIGS. 33-35 illustrate the steps for delivery of the gastrointestinalimplant device using the low profile catheter described in conjunctionwith FIGS. 32A-32B. FIG. 33 is a sectional view of a portion of thedigestive tract in a body illustrating the position of agastroscope/guide tube assembly.

The small bowel is accessed endoluminally by passing a semi-rigid tubeinto the stomach and into the pylorus 108 and proximal duodenum,inflating the bowel with a fluid, preferably water, and then passing athin, flexible catheter with a large, atraumatic ball tip through thebowel.

A guide tube 4300 is placed over the end of a gastroscope 4302. Theguide tube/gastroscope assembly is then placed through the patient'smouth, down the esophagus and into the stomach 102. The assembly is thenpassed into the pylorus 108 and the duodenum 104.

The guide tube 4300 has an inner diameter of approximately 0.63 inch (16mm) and an outer diameter of approximately 0.70 inch (18 mm). It isapproximately 30 inches (76.2 cm) in length and is made of a flexiblepolymer such as urethane with a flat wire wrap to provide kinkresistance and pushability. The distal end of the guide tube 4300 canhave a short, flexible end to minimize trauma to the pylorus 108.

Once in place, fluid is introduced through the channel of thegastroscope 4300 to inflate the intestine distally. Saline or water arepreferred but air or carbon dioxide (CO₂) can also be used. About500-1000 cc of fluid is introduced for delivery of a 4 foot length ofsleeve. Shorter sleeves require less fluid because the length ofintestine to distend is less. Likewise, longer sleeves require morefluid. After the fluid is introduced, the gastroscope is removed fromthe guide tube.

If desired, the gastroscope 4203 can be removed from the guide tube 4300and a balloon catheter can be introduced to deliver the fluid. Theballoon catheter is delivered to the pylorus and inflated to roughly0.394-0.591 inches (10-15 mm) to seal the intestine. A balloon catheterhas already been described in conjunction with FIG. 18.

FIG. 34 is a sectional view of a portion of the digestive tract in abody illustrating the distal portion of the catheter assembly extendingfrom the distal portion of the guide tube 4300. The catheter assembly4250 is advanced through the guide tube 4200 after the gastroscope 4302has been removed from the guide tube. The ball 4218 at the end of thecatheter assembly 4250 provides an atraumatic, leading tip to thecatheter such that the catheter follows the contour of the intestines.

FIG. 35 is a sectional view of a portion of the digestive tract in abody after the gastrointestinal implant device of FIG. 28 has beendelivered. The anchor of the gastrointestinal implant device is locatedinside the delivery tube 4222, which is located through the pylorus 108.A marker on the proximal end of the catheter 4200 aligns with acorresponding marker on the guide tube 4300 when the catheter is fullyinserted. Once the gastrointestinal device is in place, the sleeveretention wire 4208 in the catheter 4302 which holds the sleeve 202 inplace and also holds the ball 4218 to the distal tip of the catheter canbe removed as discussed in conjunction with the catheter system shown inFIGS. 16A-16C. As the sleeve retention wire is pulled back in a distaldirection, both the ball 4400 and the distal end of the sleeve 4500 arereleased. Fluid is then introduced through the third lumen 4206 in thecatheter to open the sleeve 202 and expand the sleeve away from thecatheter shaft 4200. Water or saline are preferred fluids although airor CO₂ can be used. Approximately 100-200 cc is injected. The fluidexits the catheter at a mid point skive hole 4502 and travels in both adistal and proximal direction. Approximately 20 cc of fluid is theninjected through the second lumen 4204 and exits the distal skive hole4216. This fluid lifts the distal end of the sleeve 202 off the innercatheter shaft 4200.

The guide tube 4300 is then removed and the gastroscope re-introducedinto the stomach and through the pylorus 108 to view the duodenum. Theproximal anchor is then deployed by pulling back on the delivery tube4222, which is connected to the proximal end of the catheter. After theanchor is deployed, the catheter system 4250 is withdrawn from thepatient. The catheter 4302 has no edges that could catch on the sleeve202 as it is pulled back through the pylorus 108 and the stomach 102 andthe esophagus because the ball is left behind. This zero profilecatheter design is important since it is typically very difficult towithdraw devices from the gastro-intestinal tract while leavingcatheters or other devices behind.

A method for accessing the small bowel by passing a catheter through themouth has been described in conjunction with FIGS. 33-35. The lowprofile catheter can also be used for accessing the small bowel throughan incision in the stomach. Instead of delivering the catheter throughthe top of the stomach as shown in FIG. 33, the catheter is deliveredthrough the stomach, for example, through an incision at position 4304in FIG. 33. The bowel is filled with a fluid, preferably water, and thenthe thin, flexible catheter with a large, atraumatic ball tip throughthe bowel is passed through the bowel as described in conjunction withFIG. 33-35.

FIGS. 36-38 illustrate embodiments for attaching a releasable sphericalshaped element to the distal end of the catheter. FIG. 36 is a plan viewof the distal end of the catheter system illustrating a releasable balltip mechanism. As discussed in conjunction with the catheter systemshown in FIG. 32, a sleeve retention wire 4208 travels through secondlumen 4204 in the catheter shaft 4200 exits the second lumen 4204through proximal skive hold 4218 and re-enters the second lumen throughdistal skive hole 4216.

The ends of a wire, or thread 4600 are attached to the ball 4218 and thethread 4600 is looped through sleeve retention wire 4208 to hold theball 4218 at the distal end of the inner shaft 4200 of the catheter. Theball 4218 is released by pulling back on sleeve retention wire 4208 withfitting 4200 (FIG. 32A) until thread 4600 is no longer held by sleeveretention wire 4208. The ball 4218 then falls off the distal end of theinner shaft of the catheter 4200 and exits the body through normalperistalsis through the intestines.

FIG. 37 is a plan view of the distal end of the catheter illustrating analternative embodiment of a releasable ball tip mechanism. The innershaft 4200 fits in recess 4706 in the ball 4218. The sleeve retentionwire 4208 exits the inner shaft 4200 through proximal skive hole 4214,pierces the sleeve 202 and re-enters the inner shaft 4200 through distalproximal skive hole 4216. The distal end of the sleeve retention wire4208 is formed into a coil shape 4700 and sits in a pocket 4702 in theball 4218. The pocket 4702 is connected to the recess 4702 through hole4704, which is of a smaller diameter than the recess 4702 and the pocket4700. The distal end of the sleeve retention wire 4208 is annealed sothat the sleeve retention wire 4208 can be pulled back in a proximaldirection and will straighten out to allow the wire to pass through hole4704.

FIG. 38 is yet another embodiment of a releasable ball tip mechanism.The inner shaft 4200 fits in recess 4706 in the ball 4218. The sleeveretention wire 4208 exits the inner shaft 4200 through proximal skivehole 4214, pierces the sleeve 202 and re-enters the inner shaft 4200through distal proximal skive hole 4216.

The ball 4218 includes two holes 4800, 4802 extending from the recess4706 to the exterior surface of the ball 4218. The distal end of thesleeve retention wire 4208 passes through hole 166 and is looped backinto hole 167. As the sleeve retention wire 4208 is pulled proximally,the wire 4218 is pulled back through hole 4802 and then through hold4800 and the ball 4218 is released from the distal end of the catheter.

FIG. 39 is a cross sectional view of an alternative embodiment of asolid spherical shaped element. A ball 4900 is fabricated in two halves,4902 and 4904. The sleeve retention wire 4006 fits into an S shapedtrack 4908. The S shape of the track 4908 creates sufficient friction tohold the ball on the end of the catheter during delivery of thegastrointestinal implant device. The sleeve retention wire 4600 fitssnugly in the channel 4908 but can be pulled proximally to release thesleeve retention wire 4600 from the ball 4900. The catheter shaft fitsin the recess 4906.

A low profile balloon can be used instead of the ball 4218 at the distalend of the catheter. FIGS. 40A-40B is a plan view of the distal end ofthe catheter shown in FIG. 34 with a low profile balloon. In theembodiment shown, a low profile balloon replaces the ball at the distalend of the catheter shown in FIG. 34. FIG. 40A is a plan view of thedistal end of the catheter with an inflatable spherical shaped element.FIG. 40B is a plan view of the distal end of the catheter after theinflatable spherical shaped element has been inflated;

Referring to FIG. 40A, a silicone, TPE, or latex sleeve 202 is attachedto the distal end of the catheter shaft 4302. Filling holes 5010 connectwith the inner lumen of the catheter to provide a passage for inflationof an inflatable spherical shaped element (balloon) 5008. The balloon5008 is attached to the shaft 4302 with a metal band 5000 that has atapered proximal transition 5002 to minimize edges that could catch onthe sleeve 202 after delivery of the sleeve 202. The metal band 5000 isabout 0.003-0.005 inches (0.076-0.127 mm) thick. The balloon 5008 can bethin wall molded, tubular polyurethane or silicone. The balloon isstored along the distal catheter shaft 4302 with the distal end pushedinto the lumen of the catheter shaft and attached to the catheter shaft4302 with a plug 5006 to keep the balloon from expanding beyond the tipof the catheter.

FIG. 40B illustrates the distal end of the catheter 4302 after theballoon 5002 has been expanded into a spherical shape. The balloon isexpanded by fluid, which flows through the catheter shaft and enters theballoon 5008 through the fluid passage holes from the catheter shaft.The plug 5006 at the end of the catheter shaft ensures that the balloonacts like the ball shown in the embodiment in FIG. 40 by limitingexpansion of the balloon beyond the tip of the catheter and the plugalso provides some lateral strength to the balloon. By replacing theball with a balloon at the distal end of the catheter, the distal tip ismore stable for axial compression. Also, the catheter will not deflectwith side loading.

The further one tries to pass a device into the intestine, the moredifficult it is since friction and tortuosity increase. FIG. 41 is aplan view of an alternative delivery system for delivering agastrointestinal implant device. The delivery system enables delivery ofa long sleeve into the intestine and includes a distal pill with foldedsleeve material inside. Peristalsis carries the pill distal in theintestine, causing the sleeve material to unfurl.

The delivery system is not limited to the delivery of a distal sectionof the sleeve for this embodiment of the gastrointestinal implantdevice. As described in conjunction with FIG. 28, the gastrointestinaldevice includes an anchor 2810 and a sleeve 202. The proximal section ofthe sleeve 202 is fully deployed and some amount of the distal sectionof sleeve 202 is packed into a pill 5100.

The gastrointestinal implant device is delivered as previously describedinto the proximal intestines. Once deployed in the intestines,peristalsis from the natural activity of the intestine pulls the pill5100 distally through the intestine. As the pill is pulled distally, thedistal section of the sleeve 202 pulls out of the pill and deploysstraight in the intestine. Peristalsis pulls the pill through theremainder of the intestines and the pill finally exits the body.

A one-foot length of sleeve material can be packed into a pill withlength of 1 inch (25.4 mm) and diameter of 0.47 inch (12 mm). Therefore,if one only wishes to pass the catheter 2 feet into the intestine fordelivery of the gastrointestinal device, the pill 5100 enables a 3 footsleeve to be delivered with the additional 1 foot distal section of the3-foot sleeve delivered in the pill 5100.

FIG. 42 is a plan view of another embodiment of the delivery mechanismshown in FIG. 41. The delivery mechanism enables delivery of a longsleeve into the intestine and includes encapsulated sleeve materialsformed into pill shapes. Each pill dissolves in the body at differentrates enabling the sleeve to be pulled distally by peristalsis as itunfolds once the pill covering dissolves.

The delivery mechanism is shown for delivery of the gastrointestinalimplant device described in conjunction with FIG. 28. The first sectionof the sleeve 202 is fully deployed after the gastrointestinal implantdevice has been delivered into the proximal intestine as previouslydescribed. A plurality of distal sections of the sleeve 202 are coatedto form a plurality of dissolvable pills 5200, 5202, 5204. The coatingsapplied to form each respective pill 5200, 5202, 5204 are made of adissolvable material, with each coating tailored to dissolve atdifferent times depending on the polymer make up and the environment.Each pill 5200, 5202, 5204 is carried distally by peristalsis. Thecoating on the first pill 5200 is selected to dissolve first. After thecoating on the first pill 5200 has dissolved, the second and third pills5202 and 5204 pull the compacted sleeve 202 distally. The coating on thesecond pill 5202 dissolves next, as the third pill 5204 pulls the sleevemore distally. Finally, the coating on the third pill 5204 dissolves andthe sleeve 202 is fully deployed. The plurality of dissolvable pillsenables the ultimate delivery of many feet of sleeve material with thesimpler delivery of only an initial 1-2 foot section of the sleeve intothe proximal intestine. As described in conjunction with the embodimentshown in FIG. 41, a one-foot length of sleeve material can be packedinto a pill with length of 1 inch (25.4 mm) and diameter of 0.47 inch(12 mm).

A number of biodegradable materials may be used for the coatings on thepills including polyethylene glycols (PEG), polylactic acids (PLA) andpolycaprolactones (PCL). These materials are made in formable resins orin liquids that can be converted to solids through various types ofchemical and photochemical reactions. These materials break down intochemicals that are safe to internal tissues. These resins are madebiodegradable by formulating a base molecule with a hydrolyticallyunstable link within the base chain.

For example, PEG is made biodegradable by incorporating lactic acid intothe base chain. One end of the lactide molecule forms a link that willbreak down rapidly in the presence of water. One means of controllingthe rate of degradation is by varying the number of lactide elementswithin the base chain. The greater the number, the faster the chain willbreak down. Additionally, the percent solids or density of the resultingsolid is varied to alter degradation rates. Denser materials take longerto break down. Also, hydrolytically unstable bonds break down faster inelevated pH environments. Such an environment occurs naturally withinthe small intestines, on the outside of the sleeve where bile andbicarbonates are deposited.

FIGS. 43A-43C illustrate a method for delivering an alternate embodimentof the catheter system 4250 having a central lumen for placement over aguide wire. FIG. 43A is a sectional view of a portion of the digestivetract in a body illustrating an enteroscope 5300 extending through thestomach, through the pylorus 104 to the duodenum 104. A guide wire 5302is then passed through the enteroscope 5300. After the guide wire hasbeen passed through the enteroscope 5300 is removed. FIG. 43B is asectional view of a portion of the digestive tract in a bodyillustrating the guide wire 5302 extending through the stomach 102 andthe duodenum 104 after the enteroscope 5300 has been removed. Thecatheter system follows a guide wire 5302 through the esophagus, thestomach 102, and the pylorus portion 108 of the stomach 102 to theduodenum 104. FIG. 43C is a sectional view of a portion of the digestivetract in a body illustrating the catheter extending through the stomach102 and duodenum 104 over the guide wire 5300. After thegastrointestinal implant device has been delivered, the catheter 4200 ispulled back through the stomach. After the catheter has been removed,the guide wire 5302 is pulled back through the intestines and thestomach 102.

An advantage of the wave design is the ability to form an anchor havinga very flat compliance curve over a very long range of diameters. Ingeneral, referring now to FIG. 44, exemplary compliance curves show theradial force exerted by different devices as they are radiallycompressed. This means that the force against the tissue issubstantially constant, even as the intestine contracts. Such acompliant device is less traumatic to the surrounding tissues. Exemplaryspring rates of the above-described wave anchors are an order ofmagnitude less than mesh-type stents. Additionally, the resulting springrates of the wave anchors are about half that of a typical Nitinol stentmade from tubing. Further, the range of motion of commercial stents isless than about 0.5 inches whereas the wave anchors can operate in arange of up to about 1.5 inches with a substantially flat compliancecurve. Exemplary test results are provided in Table 1 for known stentand for a number of other devices including wave anchors.

TABLE 1 Test Results Mesh-type Wave- Wave- Laser-cut Stent 0.014 0.016Laser-cut 1 2 Spring Rate 1.714 0.0438 0.0722 0.168 (long) 0.253(lbs./inch): 0.240 (short) Approx. Range 0.3 1.0 1.0 0.5 0.35 (inches):

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

1. A method of treatment comprising the steps of: with an anchor in theduodenum, anchoring a proximal portion of an unsupported flexiblesleeve, open at both ends, to receive chyme from the stomach; andextending the unsupported flexible sleeve distally into the duodenum. 2.The method of treatment of claim 1, wherein the anchor is retainedwithin the duodenal bulb.
 3. The method of treatment of claim 1, whereinthe anchor has a relaxed diameter of at least about 40 millimeters. 4.The method of treatment of claim 3, wherein the anchor has a relaxeddiameter of at least about 45 millimeters.
 5. The method of treatment ofclaim 1, wherein a relaxed length of the anchor is between one and twoinches.
 6. The method of treatment of claim 1, wherein the sleeve lengthis equal to or greater than one foot.
 7. The method of treatment ofclaim 6, wherein the sleeve length is less than or equal to five feet.8. The method of treatment of claim 1, wherein the anchor iscollapsible.
 9. The method of claim 1, wherein the sleeve is extendedprior to anchoring the sleeve.
 10. The method of treatment of claim 1,wherein the anchor comprises a stent including a network of struts. 11.The method of treatment of claim 1, wherein the anchor comprises acompliant wave anchor.
 12. The method of treatment of claim 1, whereinthe anchor is a collapsible anchor comprising barbs for insertion intotissue as the anchor expands to anchor the proximal portion of thesleeve in the duodenum.
 13. The method of treatment of claim 1, whereinthe sleeve is of a length that chyme exiting the stomach funneledthrough the proximal end of the sleeve exits the sleeve through thedistal end below the ligament of Treitz.
 14. The method of treatment ofclaim 1, wherein the sleeve is formed of polyethylene.
 15. The method oftreatment of claim 1, further comprising: anchoring the proximal portionof the sleeve to the duodenum with barbs extending from the exteriorsurface of the anchor.
 16. The method of treatment of claim 15, whereinthe barbs are bi-directional.
 17. The method of treatment of claim 15,wherein the barbs anchor the unsupported flexible sleeve to musculartissue of the duodenum.
 18. The method of treatment of claim 1, whereinan anti-buckling device is coupled to the sleeve, the anti-bucklingdevice extending from below the anchor to the distal end of theunsupported flexible sleeve.
 19. The method of treatment of claim 1,wherein the sleeve allows enzymes secreted in the duodenum to passthrough the duodenum outside the sleeve.
 20. The method of treatment ofclaim 1, wherein the unsupported flexible sleeve and anchor are appliedto the duodenum and taken from an esophageal catheter.
 21. The method oftreatment of claim 1, wherein the unsupported flexible sleeve and theanchor are removed through the esophagus.
 22. A method of treatingType-2 diabetes comprising: with an anchor in the duodenum of a diabeticpatient, anchoring a proximal portion of an unsupported flexible sleeve,open at both ends, to receive chyme from the stomach of the diabeticpatient; and extending the unsupported flexible sleeve into the duodenumto have a therapeutic effect on diabetes.
 23. The method of claim 22,wherein the anchor is retained within the duodenal bulb.
 24. The methodof treatment of claim 22, wherein the anchor has a relaxed diameter ofat least about 40 millimeters.
 25. The method of treatment of claim 24,wherein the anchor has a relaxed diameter of at least about 45millimeters.
 26. The method of treatment of claim 22, wherein a relaxedlength of the anchor is between one and two inches.
 27. The method oftreatment of claim 22, wherein the sleeve length is equal to or greaterthan one foot.
 28. The method of treatment of claim 27, wherein thesleeve length is less than or equal to five feet.
 29. The method ofclaim 22, wherein the anchor comprises a stent including a network ofstruts.
 30. The method of claim 22, wherein the anchor comprises acompliant wave anchor.
 31. The method of claim 22, wherein the sleeve isof a length that chyme exiting the stomach funneled through the proximalend of the sleeve exits the sleeve through the distal end below theligament of Treitz.
 32. The method of claim 22, wherein the diabeticpatient is non-obese.
 33. The method of claim 22, wherein the sleeve isextended prior to anchoring the sleeve.
 34. The method of claim 22wherein the sleeve is coated with silicone.
 35. The method of claim 22,wherein an anti-buckling device is coupled to the sleeve, theanti-buckling device extending to the distal end of the unsupportedflexible sleeve.
 36. The method of claim 22, wherein the sleeve allowsenzymes secreted in the duodenum to pass through the duodenum outsidethe sleeve.
 37. The method of claim 22 further comprising inserting theunsupported flexible sleeve with a catheter.
 38. A method of treatmentcomprising the steps of: within the duodenum, anchoring an unsupportedflexible sleeve, the sleeve open at both ends, to receive chyme from thestomach, at least a portion of the sleeve being impregnated with anactive compound.
 39. The method of claim 38, wherein the active compoundcomprises a drug that reduces inflammation.
 40. The method of claim 39,further comprising extending the unsupported flexible sleeve into thejejunum.
 41. The method of claim 38, wherein the active compoundcomprises a anti-hunger hormones.
 42. The method of treatment of claim38, wherein the anchor has a relaxed diameter of at least about 40millimeters.
 43. The method of treatment of claim 42, wherein the anchorhas a relaxed diameter of at least about 45 millimeters.
 44. The methodof treatment of claim 38, wherein a relaxed length of the anchor isbetween one and two inches.
 45. The method of treatment of claim 38,wherein the sleeve length is equal to or greater than one foot.
 46. Themethod of treatment of claim 45, wherein the sleeve length is less thanor equal to five feet.